A detergent dishwashing composition is known from GB No. 1 224 777 (Armour) which is intended for use at substantially neutral pH and which contains in addition to an acid orthophosphate, encapsulated sodium tripolyphosphate with the object of providing good cleaning action over an extended period of time.
It is also known to wash fabrics in two steps. Thus GB 996 193 (Henkel) describes adding a first concentrate to water to form a wash liquor and subsequently adding a second concentrate to the same liquor. By suitable choice of components in these concentrates, enhanced bleaching of fabrics can be obtained.
U.S. Pat. No. 2,381,960 (Dupont) describes the delayed addition of pyrophosphate to orthophosphate containing liquors for water softening, the pyrophosphate being added prior to the formation of a macroscopic precipitate of calcium orthophosphate.